@PinkMimosa
Owwww, you are literally the sweetest person ever. What a really, lovely, supportive comment.
OP, in the kindest way, Dd's boyfriend's mum checking with you is a bonkers idea. I'm sure once you've had a sleep and reflect in the morning, you will also realise this.
The family calendar is a great idea. (Think that was also pink mimosa - you are a good egg!) I recommend the app Time Tree.
DD has forgotten that you did used to have family traditions (you mentioned shows, seeing the Christmas lights and windows, putting up the tree together... But as she got older, lost interest and so these activities stopped?)
DD has clearly been involved with boyfriends family and enjoyed the nostalgia. Get the Time Tree app. And schedule in some of those forgotten traditions with her and her boyfriend.
I know Xmas is over now, but how about Chinese new year in Jan? Add a date on the calendar app that you will have a takeaway night together or all sit around and make dumplings.
Save a date for Pancake day. St. Paddy's Day. Add dates in for next Xmas for tree decorating and mulled wine night. Xmas light switch on in town?
She obviously wants those things again and wants the effort made (rightly or wrongly) on your part to organise them, like boyfriends mum does. That's why boyfriends mum is popular right now - DD is naturally favouring the person who is making the most effort - by making her feel good (with lovely, nostalgic, family xmassy things)
Sleep on it. Download Time Tree (or any other shared calendar app) get some dates in there for family nights. Just a games night with some wine. You and DP against DD and Boyfriend could be a fun night for you all?
Also, don't text boyfriends mum asking her if he has any plans on the days you put Into the calendar... You will look unhinged.